Oslo, Norway—Vitamin K status is heavily associated with COVID-19-related inflammation—more strongly, in fact, than vitamin D deficiency, according to a new article published inFrontiers in Nutrition.

The article was written by a research group from the Canisius-Wilhelmina Hospital in the Netherlands, in collaboration with the vitamin K2 manufacturer Kappa Bioscience.

Pathology during COVID-19 infection arises partly from an excessive inflammatory response with a key role for IL-6. “IL-6 is a pro-inflammatory cytokine that plays a key role in the development of severe COVID-19 and is regarded as an important therapeutic target,” explained senior author Jona Walk, M.D., Ph.D., in a press release.

Both vitamins D and K have been proposed as potential modulators of this process. The research group in question assessed vitamin D and K status in 135 hospitalized COVID-19 patients in relation to inflammatory response, elastic fiber degradation, and clinical outcomes.

Comparing the patients with good outcomes and with poor outcomes:
  • Vitamin D levels were not significantly different.
  • IL-6 levels were significantly higher in patients with a poor outcome.
  • Vitamin K status was associated with IL-6 levels, while vitamin D levels were only borderline statistically significantly correlated with IL-6.
  • A significant association was found between IL-6 and elastic fiber degradation.
  • Contrary to vitamin K status, vitamin D did not correlate with elastic fiber degradation.
Pulmonologist and translational researcher Rob Janssen, M.D., Ph.D., stated: “There are many vitamin D proponents from scientists and medical doctors to influencers and eminent politicians, advocating the distribution of vitamin D among the general population to reduce the burden of COVID-19. However, administration of vitamin D without K may not be without risk, as vitamin D increases the demand for K. This may cause further vitamin K depletion, which could be harmful in patients with moderate or severe COVID-19 who are without exception already vitamin K deficient. Based on our current data and previous work, I strongly suggest that vitamin K2 should be added to D supplementation, particularly against the background of the ongoing pandemic.”

The researchers have suggested an intervention trial to provide insight as to whether vitamin K administration, with or without vitamin D, could improve clinical outcomes in those with COVID-19.